License, verbatimPD
The Rijksmuseum, Amsterdam: image designated Public Domain (Public Domain Mark 1.0) in the museum's own Linked Art record.
Antoni Zürcher (vermeld op object). Silhouetportretten van J.L.E. Scheppern, C.L. Teutscher von Liesfeld, G.H. von Nitzswitz, J.A. Brendel, J.J. Colthoff, C.T.A. Alberti en J. Kroon, 1793. Rijksmuseum, Amsterdam.